Crabs STD are human parasites and live in the scalp, hair and around genital area. They are found in any part of the body. These STDs do not come from any-where, these exist from the starting of the time. Having lice in scalp is the common issues of the ladies especially for those ladies who have long hair. It is the issue that can be faced due to certain reasons including dust and sweat in scalp and other unhygienic routine. Mostly, the women or small girls having long hair have to face this issue. If they take care of these things they will never have this lice issue. A user has to act according to the instruction of the doctor.